[SOLVED] ListView: How to get the index of the currently shown (not the selected) Delegate/Item

I have a ListView which fills a Rectangle. Each Delegate of the ListView has the size of the ListView, so that only one Item of the ListView can be shown at once. To ensure this, I use "SnapMode: ListView.SnapOneItem".
But how can I know, which of the Items ist currently shown? I want to change the text of a Text Element (which is outside of the ListView) that corresponds to the currently visible ListView Item.